framework/src/org/apache/click/control/ImageSubmit.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.click.control;

import org.apache.click.Context;
import org.apache.commons.lang.StringUtils;

import org.apache.click.util.HtmlStringBuffer;

/**
 * Provides an ImageSubmit control:   <input type='image' src='edit.gif'>.
 *
 * <table class='htmlHeader' cellspacing='6'>
 * <tr><td>
 * <input type='image' value='img' title='ImageSubmit Control' src='image-submit.gif'/>
 * </td></tr>
 * </table>
 *
 * The ImageSubmit control is useful for creating custom form buttons. This
 * control can also be used for creating image areas where the user clicks on
 * a point on the image and the clicked x and y coordinates are submitted
 * with the name of the control.
 * <p/>
 *
 * See also W3C HTML reference
 * <a class="external" target="_blank" title="W3C HTML 4.01 Specification"
 *    href="http://www.w3.org/TR/html401/interact/forms.html#h-17.4">INPUT</a>
 *
 * @see Submit
 * @see Button
 */
public class ImageSubmit extends Submit {

    private static final long serialVersionUID = 1L;

    // ----------------------------------------------------- Instance Variables

    /**
     * The image path src attribute. If the src value is prefixed with
     * '/' then the request context path will be prefixed to the src value when
     * rendered by the control.
     */
    protected String src;

    /**
     * The image pixel x coordinate clicked on by the user, the default value
     * is -1. A value of -1 which means the value has not been set.
     */
    protected int x = -1;

    /**
     * The image pixel y coordinate clicked on by the user, the default value
     * is -1.  A value of -1 means the value has not been set.
     */
    protected int y = -1;

    // ----------------------------------------------------------- Constructors

    /**
     * Create a ImageSubmit button with the given name.
     *
     * @param name the button name
     */
    public ImageSubmit(String name) {
        super(name);
    }

    /**
     * Create a ImageSubmit button with the given name and image src path.
     * If the src path value is prefixed with "/" the request context path will
     * be prefixed to the src value when rendered in the control.
     *
     * @param name the button name
     * @param src the image src path attribute
     */
    public ImageSubmit(String name, String src) {
        super(name);
        setSrc(src);
    }

    /**
     * Create a ImageSubmit button with the given name, image src path, listener
     * object and listener method. If the src path value is prefixed with "/"
     * the request context path will be prefixed to the src value when rendered
     * in the control.
     *
     * @param name the button name
     * @param src the image src path attribute
     * @param listener the listener target object
     * @param method the listener method to call
     */
    public ImageSubmit(String name, String src, Object listener, String method) {
        super(name, listener, method);
        setSrc(src);
    }

    /**
     * Create an ImageSubmit button with no name defined.
     * <p/>
     * <b>Please note</b> the control's name must be defined before it is valid.
     */
    public ImageSubmit() {
        super();
    }

    // ------------------------------------------------------ Public Attributes

    /**
     * Return the input type: '<tt>image</tt>'.
     *
     * @return the input type: '<tt>image</tt>'
     */
    @Override
    public String getType() {
        return "image";
    }

    /**
     * Return the image src path attribute.  If the src value is prefixed with
     * '/' then the request context path will be prefixed to the src value when
     * rendered by the control.
     *
     * @return the image src path attribute
     */
    public String getSrc() {
        return src;
    }

    /**
     * Set the image src path attribute. If the src value is prefixed with
     * '/' then the request context path will be prefixed to the src value when
     * rendered by the control.
     *
     * @param src the image src path attribute
     */
    public void setSrc(String src) {
        this.src = src;
    }

    /**
     * Return the image x pixel coordinate clicked on by the user. The x
     * pixel value will be set after control has been processed. The default x
     * value is -1 which means the value has not been set.
     *
     * @return the image x pixel coordinate clicked on by the user
     */
    public int getX() {
        return x;
    }
 
    /**
     * Return the image y pixel coordinate clicked on by the user. The y
     * pixel value will be set after control has been processed. The default y
     * value is -1 which means the value has not been set.
     *
     * @return the image y pixel coordinate clicked on by the user
     */
    public int getY() {
        return y;
    }

    // --------------------------------------------------------- Public Methods

    /**
     * Bind the request submission, setting the field {@link Submit#clicked},
     * {@link #x} and {@link #y} if defined in the request.
     */
    @Override
    public void bindRequestValue() {

        Context context = getContext();

        // Note IE does not submit name
        String xValue = context.getRequestParameter(getName() + ".x");

        if (xValue != null) {
            this.clicked = true;

            try {
                this.x = Integer.parseInt(xValue);
            } catch (NumberFormatException nfe) {
                nfe.printStackTrace();
            }

            String yValue = context.getRequestParameter(getName() + ".y");
            try {
                this.y = Integer.parseInt(yValue);
            } catch (NumberFormatException nfe) {
                nfe.printStackTrace();
            }
        }
    }

    /**
     * Process the submit event and return true to continue event processing.
     *
     * @see org.apache.click.control.Submit#onProcess()
     *
     * @return true to continue Page event processing or false otherwise
     */
    @Override
    public boolean onProcess() {
        if (isDisabled()) {
            Context context = getContext();

            // Switch off disabled property if control has incoming request
            // parameter. Normally this means the field was enabled via JS
            // Note IE does not submit name, so we check the X value
            if (context.hasRequestParameter(getName() + ".x")) {
                setDisabled(false);
            } else {
                // If field is disabled skip process event
                return true;
            }
        }

        bindRequestValue();

        if (isClicked()) {
            dispatchActionEvent();
        }

        return true;
    }

    /**
     * Render the HTML representation of the ImageButton.
     *
     * @see #toString()
     *
     * @param buffer the specified buffer to render the control's output to
     */
    @Override
    public void render(HtmlStringBuffer buffer) {
        buffer.elementStart(getTag());

        buffer.appendAttribute("type", getType());
        buffer.appendAttribute("name", getName());
        buffer.appendAttribute("id", getId());
        buffer.appendAttribute("value", getLabel());
        buffer.appendAttribute("title", getTitle());
        if (getTabIndex() > 0) {
            buffer.appendAttribute("tabindex", getTabIndex());
        }

        String src = getSrc();
        if (StringUtils.isNotBlank(src)) {
            if (src.charAt(0) == '/') {
                src = getContext().getRequest().getContextPath() + src;
            }
            buffer.appendAttribute("src", src);
        }

        appendAttributes(buffer);

        if (isDisabled()) {
            buffer.appendAttributeDisabled();
        }

        buffer.elementEnd();
    }
}